It is also a fact that multiple of the Southern generals did not have a position, in particular, vis-a-vis slavery. Furthermore, a few of the Southern Generals...and I'd have to look again to recall which ones...were not even necessarily in favor of secession, but felt that their loyalty to their individual states trumped their loyalty to the Union (This would be a very common position for people on both sides of the Mason-Dixon to hold at that time).

I think Longstreet might be one of the better examples of a Southern General who just felt that his loyalties were, first and foremost, to his state--regardless of what he, personally, would have wanted. As I understand Longstreet, he was no personal fan of secession.